Over-arm clamp for machine tools



April 7, 1931 J. B ARMITAGE 1,799,493

OVER ARM CLAMP FOR MACHINE TOOLS Filed Aug. 7, 1924 so I FIG. 3

la '4 v ATTORNEY Patented Apr. 7, 1931 g U ITED: STATES g JOSEPH B. ARM T GE, or MIL AUKEE, isconsin, assrenon 'ro KEARNEY & 'rnncxnn 1 conronarron, orwnscr ALLIS,"WISCONSIN- I OVER-ARM CLAMP' FOR MACHINE TOOLS Application filed A u'gust 7, 1924. Serial No. 730,602.

This invention'relates to improvements in.

over-armclamps for machine tools.

It is the-object ofthis invention to provide an over-ar1n clamp which may be constructed '5 integrallywith a machine tool column and may include a portion adapted to-be. compressedinto clamping engagement with an over-arm without'flexing thewall' offthe column.

' 10 1 It win he understood thatma 501.001;

umns and, more particularlyythe columns of knee and column milling machines are usually made hollow for the purpose of mounting and: housing therein the spindle driving gearing and other equipment. It has heretofore been customary to providein such a column a flexible wall portionadapted to besprung into engagement with an over-arm carried in suitable bearings adjacent such portion.

While thereare certain advantages incident tothe construction of the clamp integrally with the column structure, it is nevertheless desirable in certain instances to-avoid subjecting the column itself to any fleXion-such 5 as is incident to the clamping of-an over-arm. It is therefore more specifically the object of this invention to provide, in a column having bearings for one or more over-arms, a.

vieldable bearing wallsection connected with the column wall but movableindependently thereof; it is further an object of this invention to mount the yieldable bearing wall member interiorly of the column wall and to provide means exteriorly of the column wall for conveniently acting upon; said bearing wall. section to compress it, against the overarm.

In the drawingsc- Figure 1 is a side'elevation of the supper portion of the column of a key and column milling machine'embodying this invention. 1 Figure 2 is an end elevation of the parts shown in Figure 1. r Figure 8 is a detail view on a slightly enlarged scale takenon the section indicated at 33 in Figure 1. Figure 4 is a detail view taken: on the section indicated at H in Figure 3, I

Figure 5 is a view similar to Figure 3 illustrating a-'-slightly'modifiecl construction.

, Like parts are identified by the same refer- 'ence characters throughout the several views.

1 The c0lumn 10 is preferably made hollow in accordance with the usual practice and is provided with side walls llanda'top wall ,12. The particular" device illustrated isof" the double over-arm type and consequently; bores extend longitudinally of the columnfor' accommodating parallel over-arms 14 and 15.

Two sets of clamps are provided for-"said. over-arms,-these clamps being'preferably located at the front-and rear of the column as.

indicated inthe accompanying drawings.

Within the column thereisprovided a horizontal web '16 which connects the side walls 11 beneath each of the: clamping bearngs hereinafter to be described andwhich {PATENT(OFFICE) i v may e'xtendfromfront torear of the column.

Supported upon theweb 16 and, through said web, connectedintegrally withthe column isa boss17'in whichthe over-arms 14:

and 15 find a bearingfThefollowin de- 7 scription of the bossandjthe' bearing'c amp at the front of the column will also serve to make clear the construction'of the corre-] sponding parts atthe rear of the column,

the two sets of clamping bearings'being preferably identical. Boss 17 is separated laterally from the side walls 11 of the column by narrow channels 18. The side portions 20 of the boss are likewise separated and 21. r The inward extentof channel22 is indicated in dotted lines in Figure 3. The

arrangement therefore ,is such that the cen;

tral portion of boss'17 comprises a compara tively rigid and immovable block of material integrally connected both below and at one end with the walls of the column, its

with the over arms. .the head28 against rotation relative to one 21 and "extend centrally into the respective bores of over-arms 14 and 15l Those po r tions of slots 24 which lie in the wall l2 of the column are of comparatively inconsiderable extent and do not. seriously interfere.

with the rigidity of the column wall.

By means of slots 24 each of theside'portions 20 of the boss 17 is rendered yieldable under a compressive force such as may be exerted in the usual way by a bolt 27 headed at28 for engagement with one of themembers 20and provided with a nut-29 at its other; end adaptedto act through a sleeve-30 upon the other of themembers 20. Suitable openings are provided in theiside walls l1 of'the column for the head 28 of the bolt and'the sleeve 30. Thus the entire clampingeiiect of the boltisiexerted directly upon theyieldable portions of the boss'to spring such portions into clamping engagement A-key at 31 secures of the yieldable boss elements 20 when the nut 29 is being turned up or unscrewed.

The relatively heavy and unyieldable central portion of boss 17 provides properly aligned surfaces toward which'the' over- .arms Hand 15 are clampedwhe'nthe nut 29 .is tightened on bolt :27-to spring'centrally each of the yieldable boss portions 20. This arrangement is conducive to accuracy and rigidity.

It will be observed that'the column as a wholefis strengthened in that its walls are not called upon to yield for clamping purposes. The only openings in the column walls are the apertures for sleeves B and head 28 and the slots-2a in the top wall 1.2. These slots, as has already been pointed out, donot extend to the front or rear of the column and consequently are not calculated-to weaken materially the strength and rigidity of the column wall.

The Figure construction illustrates a mere inversion'of the parts shown in Figure 3 whereby the channels 21 are rendered unnecessary. .The boss '17 is connected integrally with'the top wall 12 of the column and so likewise are the yieldable boss elemerits Channels 18 separate the yieldable boss elements from theside walls 11 of the column in the manner already described and thescrew-operated clamping .means maybe identical withthat described above 'exceptthat itwill now be located below the -o'verarms instead-of above the over-arms.

I claim:

1. The combination of a machine tool column having side walls and an over-arm adjustable therein, of a clamping device including over-arm gripping portions integral with said column, one of saidportions comprising a relatively immovable wall on oneside of said over-arm and positioned between opposite side walls, and another of said portions comprising a relatively-flexible member integrally connected with and housed within said column and opposed to said relatively immovable wall, whereby to be adapted to engage the over-arm with said relatively immovable wall.

2. The combination with a machine tool column having side walls and a pair of spaced over-arms adjustable therein, of a clamping device including over-arm gripping portions integral with said columnfor each of-said over-arms and comprising a relatlvely immovable wall. positioned between opposite side walls having a portion between said over-arms and adapted for contact with each, and relatively flexible members each integrally connected with said column and each housed within said column ina position to be opposed to said relatively immovable wall, whereby 'to' be adapted to engage the respective over-arms with said relatively immovable wall upon either side thereof.

3, In a device of the character described, the combination with a hollow column having a bore therethrough and provided internally with a centrally disposed boss having aire'latively inflexible wall aligned with said'bore,

anover-arm adjustable-through said bore at one side of said central boss, and a clamping element having a flexible portion housed completely within said column and adjustable centrally toward-said boss to'a position of clamping engagement with an over-arm in said bore and having another portion connected rigidly and integrally to extend be pendently of the first mentioned portion and a the column wall to restrict the 'openingof said bore, together with means for-mechanically springing said otherporti'on to restrict said bore. V

5. Assn article of nianufacturawa milling machine column provided with "a bore ;eX-

tending therethrough and adapted to receive an over-arm, said bore having an internally housed bearing having difi'erent portions, one

portion being rigidly integrally connected with a wall of said column and the other porable independently of the first mentioned portion and the column wall to restrict the opening of said bore, together with means for mechanically springing said. other portion in a dlrectlon to restrlct said bore, said means including a part extending through a wall of said column and being accessible exteriorly thereof.

6. The combination with a hollow machine tool column substantially completely enclosing an interior chamber, of a boss within said chamber, said column being provided with a bore extending through said boss, and an over-arm adjustable within said bore, said frestrict both bores simultaneously.

boss including relatively fixed and relatively flexible'clamping elements each formed integrally with the column interiorly thereof and having surfaces aligned with said bores, said flexible elements being adjustable independently of said column and without distortion thereof to restrict said bore wherebyto? clampingly engage said over-arm, together with tension means for actuating said flexible] clamping element toward said fixed element.v

7. In a device ofthe character described, .the combination with a hollow machine tool column, of a boss disposedinteriorly ofsaid column and connected integrally therewith, a

side portion of said boss being wholly free from said column, and an over-arm adjustable through said column and said boss, a slot being provided extending through the boss in the direction of said over-arm wherebyto sever from the remainder of the boss one end of said side portion, whereby to permit said portion to be sprung in the direction of said over-arm independently of said column and of the remainder. ofsaid boss.

8. In a device of the character described,

the combination with a hollow machine tool column, of aboss disposed interiorly of said column and connected at its central end and top portions integrally therewith, a side portion of said boss being wholly free from said column, and an over-arm adjustable through said column and said boss, a slot being provided extending through the topof saidcolumn into said free portion of said boss wherethe combination witha hollow machine tool column provided with spaced over-arm bores, of a boss within said column and including portions encircling said bores, the'boss portions at the'sides of said portions being housed within said column and spaced there- 4 from throughout a portion of their peripheral extent, said boss portion-s beingfree to move in a direction to restrict said bores.

10. In a device of the character described, the combination with a hollow machine tool, column provided" with spaced over-arm bores,

of a boss within said column and including tions at the sides of said portions being housed within said column and spaced there.- from throughout a portion of their peripheral extent, said boss portions being free to move in a direction to restrict said bores, to gether with a single clamping means accessible exteriorly of said column and acting upon both of said boss por'tionswhereby to portions encircling said bores, the boss por- I 11. In a device ofthef-characterdescribed, i

the combination with. a hollow column, of a boss therein, a pairof over-arms adjustable i through said columnand said boss, interiorly disposed portions. of said boss being free of said columnand the remainder of said boss for yielding movement toward said overby to permit said boss portion to be sprungin I V the direction of said over-arm independently of said column and of the remainder ofsaid boss, together with a transverse bolt projecting at its end from'said column and provided concentrically with means extending through said column into engagement with the free lateral portion of said boss.

9. In a device of the character described,

extending transversely 

